In the U.S. Pat. application Ser. No. 969,544, filed Dec. 14, 1978, as an invention related to the present invention, by Shigemori Otani, one of inventors of the present invention, "A burner for combustion apparatus" is disclosed.
The above-mentioned prior invention provides a so-called "Multistage pulverizing system" wherein as shown in FIG. 1a, an end is closed by a conical portion 2, an inclined surface 3 is provided with a number of fuel oil outflow ports 4 through which the fuel is jetted in a string-like manner, the fuel is broken up into atomized forms in the primary air passing through the orifice, and the fuel deposited on the inclined portions 3, 3' and 3" is in the form of a film and is broken up in a film-like manner at apex side portions 2' and 2" of the conical portion. That is, the prior invention relates to a burner in which even if pressure of the primary air for pulverization is low, the fuel can be extremely pulverized, that is, good atomization can be achieved. The use of the burner in accordance with the prior invention results in the quantity of fuel oil per hour, 200-300 l/hr, which means a considerable increase in the quantity of fuel oil at low pressure and under the conditions of good atomization as compared to conventional binary fluid atomizing burner, 10-20 l/hr, and binary fluid atomizing core burner (slit burner), 50-100 l/hr.
However, with the recent demand of larger type industrial furnaces and boilers, it has been required to further develop extremely large capacity binary fluid burners of more or less 1,000 l/hr in the quantity of fuel oil.
The present invention has been achieved to fulfill such a demand as noted above and provides a burner device which functions as if it were a single large-capacity burner wherein the characteristic of the burner disclosed in the above-mentioned prior U.S. Pat. application Ser. No. 969,544 is used so that the burner comprises burner units, which are plurally combined on the surface of a burner head.
The burner device in accordance with the present invention has the advantages as follows:
(a) The burner of the present invention is that a plurality of "A burner for combustion apparatus" as disclosed in the U.S. Pat. application Ser. No. 969,544 are combined as burner units to form a burner device which functions as if it were a single large-capacity burner. With this arrangement, good pulverization can be achieved with about 10% of the theoretical quantity of air for combustion, and good combustion performance may also be attained. As compared to prior arts in which only the desired number of independent burners are provided, the burner of the present invention is possible to control, adjust and manage the flames very easily since flames from burner units are in the form of a compound flame at first sight.
(b) Since an orifice for supplying only the primary air is disposed instead of inserting burner units into a central portion of the surface of the burner head, the deposition of oil drops on the surface of the bed board may be avoided, and accordingly, no scale-like carbon flour is deposited.
(c) The length and spread of the flame may be considerably adjusted by adjusting lateral movement of the burner units and orifices or by varying the angle of a frustum of the furnace head surface.
(d) It is possible to control generation of nitrogen oxide.
(e) In addition, also in precipitators of liquid pulverizing and atomizing type, spray dryers and humidifying apparatuses, it is possible to make the best use of characteristic of the present invention to anticipate effects similar to those mentioned above.